That's what readers of this NYT piece must have been asking. It reported:
"It [the I.M.F.] has urged Tokyo to make structural reforms to bolster its labor market, by, for instance, bringing women into the work force."
This seems strange since the OECD reports that the employment to population ratio for prime age women in Japan (25-54) was 71.5 percent in the third quarter of 2013, the most recent data available. By comparison it was 69.4 percent in the United States.
From comments below and other comments I have received, I realize I need to clarify my point. From all the data I have seen and accounts I have heard, Japan continues to be a very sexist society and women almost certainly face more discrimination than in the United States. I was simply saying that their problem is not bringing women into the workforce. On that score the country has done remarkably well. The employment to population ratio for prime age women rose from 67.6 percent in 2007, before the recession, to 71.5 percent in the most recent quarter. By contrast, in the United States it fell from 72.5 percent to 69.4 percent over the same period. Based on these data , getting women into the labor force is one thing that Japan seems to be doing well.
Note: numbers were corrected to show employment to population ratios for prime age women.